I was wondering if anyone can explain in what ways I can use blocking as well as increasing and decreasing. I have started my first project (http://sknittenmittens.blogspot.com/) and I was hoping to use some of these techniques. Thanks in adavance!

Is the scarf your first project? Blocking depends on the yarn you're using. If it's wool you can pin it out to size, spray it with water and let it dry completely. Here's one earlier discussion of blocking acrylic yarn.
This is probably not the ideal project to incorporate increases and decreases. Maybe a hat or a sweater would be a possibility for your next project?

The scarf is my first project. Will blocking alter the color? And I understand. I wanted to know because I am interested in learning everything I can about knitting. It is a very captivating hobby. I will keep in mind to use the increase and decrease in future projects. Thank you!